Sometimes the most valuable research turns out to be a confirmation of the obvious. Fitting that bill is the study released yesterday in the Proceedings of the National Academy of Science documenting the substantially decreased life expectancy among people in China living in areas where coal has for many decades been used to heat homes. The study is based on a long-standing policy in China of distributing coal free to residents who live north of the Huai River but not to people living south of the river. In comparing life expectancies, the study found that people living north of the river were exposed to significantly higher total suspended particulates in the air and had a life expectancy of roughly five years less than those living south of the river. That significant difference in life expectancy can be explained almost entirely by a larger mortality rate north of the Huai River from cardiorespiratory diseases typically associated with exposure to air pollution.

This is precisely the health effect one would expect to see from significant exposure to air pollution from uncontrolled combustion of coal. It is a powerful reminder that the most important environmental risks are the most basic ones. While regulators in the US wrestle with how much further to ratchet down emission controls beyond 98% often a huge cost, the most important air pollution controls are often the first 25% to 50%. I remember attending an environmental conference in the 1990s when an EPA official commented that, air pollution being a global problem, we would all be far better off if American companies were allowed to stop improving their emission controls and donate half their savings to pay for emerging countries to acquire technology to control the first 20% of their emissions. Given how the Chinese economy has grown in the last decade, China can certainly afford the costs of controlling its own air pollution, and it should do so promptly.